October 2004 - Cosmo-torun

wrapped space
by Bartosz Lew 28 Oct '04

28 Oct '04

interesting... http://edition.cnn.com/2004/TECH/space/10/21/warped.spaceII/index.html BL

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propozycji tematy licencjat/magister
by Boud Roukema 22 Oct '04

22 Oct '04

Witam, Propozycji dla licencjat/magister są tu: http://adjani.astro.uni.torun.pl/cgi-bin/twiki/view/Cosmo/LicMag Dzięki do Bartka dla komentarza :) Andrzej Strobel: Żeby możesz klejić do dokumenta tekstowy, treści jest tu, na dolę. pozdr boud ---------------------------------------------------------------------- Supervisor: B. Roukema (boud at astro.uni.torun.pl) Number of students: up to 3-4 students is possible Observational Cosmology Masters/Licencjat Project - General Outline Description: There are many possible projects which could be done as a master's thesis project, in using publicly available archival data from observational surveys to constrain one or more of the local or global cosmological parameters, either those related to shape (curvature, topology) or maybe also those unrelated to shape ("dark energy" or "dark matter"). The precise projects would be chosen in discussion with the masters students during Nov-Dec 2004. Please see http://adjani.astro.uni.torun.pl/cgi-bin/twiki/view/Cosmo/CosmoProjects for projects Boud is working on and http://adjani.astro.uni.torun.pl/cgi-bin/twiki/view/Cosmo/CosmoNews for ideas on the hottest topics in cosmology research - any of these would be appropriate if the student is sufficiently interested. Examples (1) Topology of the Universe Detection * In http://de.arxiv.org/abs/astro-ph/0402608, it seems that we may have measured the shape of the Universe, since certain parts of the cosmic microwave background seen by the WMAP satellite appear to be seen twice in different directions on the sky, due to topological lensing. The purpose of the masters/licencjat project is: * Aim: Propose and apply a further test using WMAP data which further tests the hypothesis. This requires: o Reading/writing/managing the WAMP data file with free software computer programs o Statistical analysis o Independently checking that the computer code does the algebraic and statistical analyses correctly (2) Dark Matter Detection * In http://de.arxiv.org/abs/astro-ph/0405282 the 7 year results of the DAMA/NaI dark matter direct detection experiment show a signal significant at 6.3? according to the authors. An explanation for why a signal from mirror-baryonic matter should be expected in this experiment but not in others with similar cross-section detection parameters is presented in http://de.arxiv.org/abs/0403043. * Aim: Check the experimental and theoretical claims and propose further tests o Try to find an alternative explanation for the DAMA/NaI results without going beyond the Standard Model of particle physics o Check whether the Foot et al. calculations of mirror matter properties are consistent with all the experimental data as the authors claim o Extend the Foot et al. calculations to find, e.g. a non-gravitational effect of mirror matter in stellar physics, e.g. symbiotic stars (gravitational effects of dark matter are already well studied) * More info: http://adjani.astro.uni.torun.pl/cgi-bin/twiki/view/Cosmo/NonBaryonicDarkMa… (3) Cosmic String Detection * In http://de.arxiv.org/abs/astro-ph/0410073 Kibble discusses the http://de.arxiv.org/abs/astro-ph/302547 possible detection of a cosmic string which seems to gravitationally lens a background galaxy (Sazhin et al.) In http://de.arxiv.org/abs/astro-ph/0406516 the extra pairs of lensed galaxies predicted by the hypothesis are discussed. * Aim: Understand the basics about (1) cosmic strings, (2) gravitational lensing versus cosmic string lensing, and test the hypothesis o Calculate the probability of seeing the original pair by chance o Check whether the statistics of expected numbers of lensed images are correct o Propose an independent test of the hypothesis, e.g. using radio observations and prepare an observing proposal General Requirements: * basic knowledge in astronomy, physics, mathematics, computing skills * desire to measure something about the shape of the Universe and/or dark matter or dark energy and/or cosmic strings * willingness both to learn from and to teach others interested in observational cosmology at TCfA * willingness to learn the following practical skills: touch-typing, emacs, \LaTeX, usage of wikis and/or mailing lists for communication, GPL compatible programming * participation in the "Shape of the Universe" monograph course and/or Bronek Rudak's semester 9 "Kosmologia" course: o http://adjani.astro.uni.torun.pl/cgi-bin/twiki/view/Cosmo/MonographCosmo o http://www.ncac.torun.pl/~bronek/KOS.html * Nie ma problemu jeśli student magistera lub licjencacki (jeszcze) nie dobrze mówi po angielsku, ale potrzeba znać czytać i rozumieć po angielski naukowcy ----------------------------------------------------------------------

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projects for licencjat/magister students
by Boud Roukema 21 Oct '04

21 Oct '04

witam, Apparently i should give this to Andrzej Strobel "before the end of the week" - i guess this means tomorrow (Friday) afternoon is OK. http://adjani.astro.uni.torun.pl/cgi-bin/twiki/view/Cosmo/LicMag i've including internal twiki links with the full URL so that Andrzej Strobel will (hopefully) include this in the text he distributes. Any comments (you could edit the twiki directly if you wish...)? pozdr boud

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cosmic string detection from close pairs of galaxies ?
by Boud Roukema 21 Oct '04

21 Oct '04

Witam, We have an interesting candidate for Dark Matter. It seems there is also an interesting candidate for cosmic string detection: http://adjani.astro.uni.torun.pl/cgi-bin/twiki/view/Cosmo/CosmoNews#cosmic_… (i've shifted CosmoNews to the twiki, so that it's easier to edit etc.) pozdr boud

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Re: Journal Club
by Boud Roukema 19 Oct '04

19 Oct '04

Witam, Agnieszka: i think what Bartek and i answered to your question about OGLE/MACHO/EROS was wrong - if MACHOs are mirror matter, then there is no problem with violating nucleosynthesis. As far as nucleosynthesis constraints are concerned, Omega_MACHO *could* be as big as 0.20, provided that it is *not* baryonic. So it seems to me, anyway. So the possible argument against MACHOs being mirror matter and providing Omega_MACHO=0.20 (Omega_m - Omega_baryon = 0.25 - 0.05 =0.20) depends on which observational/Galaxy-structure analysis of OGLE/MACHO/EROS you believe. E.g. http://de.arxiv.org/abs/astro-ph/0303100 Afonso et al 2003 say expected "optical depths" towards the Galactic Bulge are something like 4e-7 for "ordinary" stars and 8e-7 if there is a population of brown dwarfs, probably just citing these from Paczynski 1991 and Griest 1991. What they find is about 9e-7, while the first OGLE results (1994) found 33e-7 which is about 4 times higher, and Afonso et al say they can't calculate an optical depth for OGLE II because the experimental parameters (detection efficiency) are not published. Even if Afonso et al are right, there's still the possibility that the Om_b/Om_b' \approx 0.5 is right (instead of 0.2) and that there are at least two different non-baryonic types of dark matter in significant quantities (the Universe often turns up out complicated than we expect, at least in terms of new particles...), in which case Omega_mirror \approx 0.1 instead of 0.05 and it could be the MACHO population. So probably the challenge is to see if there is some experimental way of distinguishing a baryonic MACHO from a mirror-baryonic MACHO... pozdr boud On Wed, 13 Oct 2004, Agnieszka Slowikowska wrote: > Witam, > > zapraszam na kolejny Journal Club, ktory odbedzie sie w najblizszy piatek > o godzinie 10.15 w sali seminaryjnej kamieniczki CAMK. > > Boud Roukema opowie nam o "Mirror matter and the 7 yr DAMA NaI results: > has DM already been detected?". > > > Pozdrawiam, > aga > >

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The universe may be revealing its shape, new findings suggest
by Andrzej Marecki 18 Oct '04

18 Oct '04

Have you seen this?? http://www.world-science.net/exclusives/exclusives-nfrm/041005_univshape.htm am

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content of journal club talk
by Boud Roukema 14 Oct '04

14 Oct '04

hi, i think Agnieszka forgot to send the abstract of my talk (this seems to be the habit here - only title, no abstracts...) pozdr boud > Witam, > > On Mon, 27 Sep 2004, Agnieszka Slowikowska wrote: > > > Witam, > > > > bardzo prosze wszystkich spikerow Journal Clubu o przesylanie tytulow > > Proponuję spikować (jak spikerem, muszę spikować) o: > > "Mirror matter and the 7 yr DAMA NaI results: has DM already been detected?" > > http://adjani.astro.uni.torun.pl:9673/zwicky/CosmoNews > http://de.arXiv.org/abs/astro-ph/0405282 > http://de.arXiv.org/abs/astro-ph/0211067 > http://de.arXiv.org/abs/astro-ph/0403043 > http://de.arXiv.org/abs/hep-ph/0402267 > > Chyba będę przygotować coś w pdf przez pdflatex. > > pozdr > boud > > > wystapien. Program mozna znalezc na stronie: > > > > http://www.ncac.torun.pl/~aga/Journal-Club.html > > > > Przypominam, ze wystapienie nie powinno byc dluzsze niz 20 minut i powinno > > dotyczyc ciekawych osiagniec astronomicznych lub astrofizycznych > > opublikowanych ostatnio w profesjonalnych magazynach astronomicznych. > > > > Journal Club odbywa sie w CAMKu o 10.15 w piatki. > > 1 pazdziernika nie ma JC, poniewaz jest inauguracja roku akademickiego > > 2004 / 2005. > > > > Pozdrawiam, > > aga >

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AA/2004/2055 (fwd)
by Boud Roukema 13 Oct '04

13 Oct '04

Witam, Well, A&A has come up with a new excuse: ---------- Forwarded message ---------- > Date: Wed, 13 Oct 2004 14:03:30 +0200 > From: aanda.paris at obspm.fr > To: boud at astro.uni.torun.pl > Subject: AA/2004/2055 > > 13/10/2004 > > Dr Boudewijn F. Roukema > boud at astro.uni.torun.pl > > Our Ref. : AA/2004/2055 > > Dear Boud, > We were not aware of this paper in astro-ph by the Healpix team. > Now that this is published, we do not think it possible for A&A to > consider publishing a similar paper, even if you derived it > independently, with different details. > The motivation you had to publish it, is now gone. So you can > understand that we can not unfortunately consider further your paper > for A&A, > > with best wishes, > The Editors > The motivation you had to publish it, is now gone. So you can Hmmm... In this case, it seems to me that the A&A Editors are stating that they consider electronic publication as important as refereed journal publication and that peer review of scientific papers is unnecessary! It is clear that some time we are going to have to reorganise the methods by which A&A editors make decisions. After all, it's we the astronomers who are supposed to run A&A, not the other way around. When the Editors start saying that peer-reviewed publications is unnecessary, we have a problem... However, that's something for the long term. pozdr boud

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Re: AA/2004/2055
by Boud Roukema 12 Oct '04

12 Oct '04

Dear Editors, On Wed, 29 Sep 2004 aanda.paris at obspm.fr wrote: > 29/09/2004 > > Dr Boudewijn F. Roukema > boud at astro.uni.torun.pl > > Our Ref. : AA/2004/2055 > > > Dear Boud, > > We are sorry that we cannot consider your paper for publication in > A&A, since it is based on the HealPix software, that has been The second half of the above statement is false. Our paper contains algebra regarding a system of pixelising the sphere which is independent of any software implementation. It is not based on the HealPix software. It is based on the cited paper: Gorski et al. (1999a/b), which presents the outline of a pixelisation system but not its full solution. The solution requires a small, but original and highly necessary (given its non-availability to astronomers) amount of algebra and elementary calculus. Nevertheless, it is understandable that you are worried that the derivation in our paper might be just an extract of the non-free-software (see below) HEALPix software package. In principle, some part of the solution in our paper probably is, in some indirect sense, implicitly present in the HEALPix package. However, in the context in which free software is receiving increasing support, even from governments in Western Europe, it is unreasonable to expect astronomers to search through non-free code in order to find the necessary algebra. Surely it is more useful for them to see the algebraic derivation directly as a solution to the only partially solved problem in Gorski et al. (1999a/b), so that they neither have to rederive it algebraically, nor search through non-free computer code. A similar situation occurs when, say, an article A is submitted to A&A which has content which solves an unsolved problem in an article B cited in the bibliography, but it is well-known that the authors of the cited article B are aware of the full solution to their problem; and it is also known that many astronomers C communicate directly with B, in private, but other astronomers D need to independently rederive the solution if they do not wish to enter into a direct working relationship with authors B. Wouldn't it in this case be reasonable to send the article to an independent referee, independent of all astronomers known to be close colleagues of any of the authors A or B, while asking the referee to judge whether or not the content is independent of the non-freely distributed work of authors B? Please note: > developped by Gorski et al, and is still actively developped and > improved, and is widely distributed on the web (now on the ESO web > site), and is widely used. It is distributed freely, with all the The Gorski et al software is *not* distributed under a free software licence (see http://www.gnu.org) It is formally correct that it is distributed at zero cost, but it is *not* "free software"; it may not be redistributed without the permission of its authors. This violates software freedoms 2 and 3: http://www.gnu.org/philosophy/free-sw.html (en) http://www.gnu.org/philosophy/free-sw.fr.html (fr) All four software freedoms (0, 1, 2, 3) are part of the fundamental basis of the GNU/Linux free software system. > could have done this paper, and if they have not judged it worth > while, you have just to convince them to do so, or at least > collaborate with them to do so. A paper like this, with them as > co-authors, would not have this problem. But apparently they judge > that the publication on the web as it is now is sufficient, Surely the authors of a non-free software package related to a cited paper are not in a neutral position regarding algebra derived from that cited paper; they may (either correctly or wrongly) believe that any related work is necessarily unoriginal. If a paper is submitted, which, for example, is stated to be based on Bloggs et al. (1995n) and it is suspected that the submitted paper contains similar content to Bloggs et al. (1996d), then is it reasonable to insist that the submitting authors collaborate with Bloggs et al. (1996d), even if Bloggs et al. "could have done" the submitted paper and "have not judged it worth while"? Or would it not be more reasonable to send it to a referee independent of both the submitting authors and Bloggs et al. ? Finally, you might also want to note that Gorski et al. themselves have implicitly *approved* the scientific value of publication of our paper. On 8 Sep 2004, we proposed co-authorship to the HEALPix software authors (Krzysztof Gorski <Krzysztof.M.Gorski at jpl.nasa.gov>, Eric Hivon <efh at ipac.caltech.edu>, Frode Hansen <Frode.Hansen at roma2.infn.it>, "Benjamin D. Wandelt" <bwandelt at uiuc.edu>) http://cosmo.torun.pl/pipermail/cosmo-torun/2004-September/000523.html (first message in http://cosmo.torun.pl/pipermail/cosmo-torun/2004-September/ ) and we pointed out that if we did not hear any response by 22 Sep, we would presume that they were uninterested. We had a constructive discussion with Frode, and he chose not to be a co-author, at least pending possible future discussion. The others did not reply directly, but they replied one day before the 22 Sep deadline, by publishing a paper similar to the one we had already sent them: http://de.arxiv.org/abs/astro-ph/0409513 In this paper, BTW, in formulae (13) and (14), there is an inspiration from our own notation in Sections 2.2.1 and 2.2.2 of our paper, but without citation. Their derivation is clearly independent work from ours (while they were clearly motivated and inspired by our work, they were clearly capable of doing it independently); our work is clearly independent from theirs. However, the fact of their publishing (electronically, at least) in response to receiving our paper suggests that they consider the content valuable to the scientific community and *not* present in their non-free software package. Their paper 0409513 is presented in ApJ referee format; would it be reasonable that one independent derivation is published in ApJ but a second independent derivation is *not* published in A&A? Best regards Boud %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %%%%%%%%%%%%%% END OF PROPOSED REPLY TO A&A %%%%%%%%%%%%%%%%%%%%%%% %%%%%%%%%%%%%%%%%%%% DEADLINE mon 11 oct 2004 %%%%%%%%%%%%%%%%%%%%%%% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

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Meudon Workshop on Cosmic Topology
by Jean-Pierre Luminet 07 Oct '04

07 Oct '04

Dear colleagues, I am organizing a mini-workshop (2-3 days, a dozen of participants) about the recent developments in cosmic topology, and I would like very much to invite one of you (Andrzej Marecki, Bartosz Lew, Magdalena Cechowska) to this workshop for giving a talk. (I have already invited Boud Roukema, who has accepted.) The place will be Meudon, the date will be 8-10 march 2005. Your travel expenses as well as your hotel would be taken in charge. Other speakers/participants will be Jeff Weeks, Marcelo Reboucas (from Brazil), Jesper Gunderman (a Danish mathematician working on eigenmodes), and of course the French group : Marc Lachieze-Rey, Alain Riazuelo, Roland Lehoucq, etc. See the enclosed preliminary program. It would be really a great opportunity to meet altogether and resume the state-of-the-art of this fascinating field of cosmology together with future perspectives and collaborations. I really hope that one of you will be able to accept - please decide amongst yourselves who is most interested in participating, and confirm before 1 november. Yours, Jean-Pierre -- Jean-Pierre Luminet Directeur de recherches au C.N.R.S. Laboratoire Univers et Théories (LUTH) Observatoire de Paris-Meudon, 92195 Meudon cedex, France --- tel:(33) 01 45 07 74 23, fax:(33) 01 45 07 79 71 --- http://www.luth.obspm.fr/luminet.html

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